Self-centering positive locking grapnel



1961 c. G. HOPPER 2,991,112

1 SELF-CENTERING POSITIVE LOCKING GRAPNEL Filed Feb. 24, 1960 INVENTOR CHARLES G. HOPPER ATTORNEY Patented July 4, 1961 fire . 2,991,112 SELF- CENTE'RING POSITIVE LOCKING GRAPNEL Charles G. Hopper, Hayward, Calif assignor t the United States of America as represented by the United States Atomic Energy Commission Filed Feb. 24, 1960, Ser. No. 10,820

3 Claims. (Cl. 294-86) 7 The present invention relates to grapnels and more particularly to self-centering positive locking grapnels.

Installations where hazardous materials are handled and processedmust employ manipulative devices and equipment having a high factor of safety, reliability and positive action. Such equipment is especially important where handling must be done in a sealed system or must be remotely controlled. Undoubtedly the most used piece of equipment for remote operation is handling apparatus (hoisting, transporting, grabbing, releasing, etc.). Such apparatus usually consists of lever arms, cranes, pulley systems, etc., used either singly or in combination. A small but most vital part of such an apparatus is the unit which actually contacts, grabs, holds or releases the hazardous material. This unit must be extremely reliable for it fails the whole system will cease to function. The present invention provides a grapnel which has the numerous characteristics necessary for dependable basic operation.

It is thus an object of the present invention to provide a grapnel which positively locks a load onto a crane system.

It is an object of the present invention to provide a grapnel which centers a load directly below the crane lift axis.

It is a further object of the present invention to provide a grapnel which will hold and release a load without the manipulation of any auxiliary securing mechanism.

It is another object of the present invention to provide a grapnel which picks up and releases loads with a minimum of visual observation.

Numerous other advantages and possible objects of the invention will become apparent to those skilled in the art from the following description of a preferred embodiment of the invention taken together with the accompanying drawing, in which:

FIGURE 1 is a perspective view of the grapnel; and

FIGURE 2 is a perspective and cutaway view of the grapnel in operation with a load secured thereto.

Referring now to the drawing the grapnel of general symmetrical conical configuration comprises a central body core '12 of conical configuration having a fiat upper surface 13 and a threaded bore 14 drilled vertically into the central body core 12 along the vertical axis thereof and terminating short of the apex of said body core. A number of supporting segments 16 are disposed symmetrically about the central body core 12 and are integral therewith, said segments extending from the upper surface 13 of the body core 12 along the conical portion thereof and converging and terminating at the apex of said body core 12. symmetrically disposed about the grapnel 11 and normal to the radial axis of said support segments 16 are a number of generally triangular shaped claws 17 mounted on and forming an extension of said support segments 16. Claws 17 flare out from the support segments 16 along a cone-shaped surface concentric with the coneshaped surface of body core 12. Each claw 17 is broad at its upper edge and decreases in width towards its apex and terminates in a point 18 short of the apex of a cone formed by the projection of the outer surface of all the claws 17. A lip 19 integral with and disposed in continuation of said claw 17 extends upward beyond the upper surface of the supporting segment 16. The lip 19 has an upper edge 21 generally semicircular in shape, said upper edge terminating in lateral edges 22 of the claw 17. Said edges 22 of the claw are in fixed spaced relation with the corresponding edges of adjacent claws, with said edges defining slots 23 running from the lip 19 to the claw point 18. The slots 23 extend into a opening 24 at the apex of the grapnel, while upon their radial axis they open into cylindrical bores 26. Said bores 26 defined by the core, adjacent segments, and adjacent claws, extend from the upper surface of the grapnel parallel with said slots into a common generally spherical opening 27 located intermediate of the apex of the body core 12 and the numerous claw points 18.

In operation, with reference to FIGURE 2, a screw eye 31 or similar device is threaded into the bore 1 4 of the grapnel, and the grapnel and screw eye are connected to a remote control system cable 36 as by a swivel. The load 32 is secured to a load support 37 comprising a rod 33 capped with an enlarged portion 34 preferably a sphere. The diameter of the rod 33 is slightly smaller than the width of the grapnel slots 23 and the sphere diameter is slightly smaller than the diameter of the cylindrical bores 26 and the spherical opening 27, but larger than the opening 24 formed by the claw points. To connect to the load, the grapnel is lowered toward the load with the rod and sphere extending upwardly therefrom. The sphere touches the grapnel and the grapnel is further lowered; the sphere slides upward forcing the grapnel to the side and finally passing over the lip 19 on the upper portion of the grapnel. Due to the semicircular configuration of the lip and the offset from the vertical axis, the

I grapnel rotates until the ball and rod become aligned with a bore 26 and associated slot 23. The rod then slips into the bore through the slot and the grapnel is then raised, forcing the ball 34 down into the bore 26 and finally into the spherical opening 27, wherein the ball 34 becomes lodged with the rod 33 extending down through the opening 24. The load is now securely locked to the remote control system and suspended directly below the vertical axis of the remote control cable.

To release the load, the grapnel is lowered until the load is at rest on a surface, slack appears in the cable, the ball then slips out of the spherical opening up through the bore until it extends above the grapnel. The grapnel is moved slightly to the side by remote control and the load then becomes disengaged from the handling system.

While the salient features of the present invention have been described in detail with respect to a single preferred embodiment it will be apparent that numerous modifications may be made within the spirit and scope of the invention and it is therefore not desired to limit the invention to the exact details shown except insofar as they may be defined in the following claims.

What is claimed is:

l. A positive locking self-centering grapnel comprising;

a cone shaped body core having a base, an apex and an intervening lateral surface;

a plurality of support segments disposed about said body core, integral with said lateral surface, and extending radially and outwardly from said lateral surface for the distance of said'apex from said base;

a plurality of thin, wedged-shaped claws united to said support segments, each of said claws having oppositely disposed edges which meet at a point and a broad outer face, said claws cojointly defining a conical surface which is concentric to said lateral surface of said body core;

the respective claws terminating in a circular array of spaced points lying below said support segments;

said claws being so spaced with respect to each other that their edges define slots along their entire length;

said body core, support segments, and claws defining cylindrical bores parallel to and in communication with said slots, said bores being of greater diameter than the diameter of said circular array; and

means for attaching said base of said body core to a hoist line.

2. A positive locking self-centering grapnel comprisa cone shaped body core having a base, an apex, and an intervening lateral surface;

an eye hook anchored in said body core at said base and coaxial with the central axis of said body core;

a plurality of support segments disposed about said body core, integral with said lateral surface, and extending radially and outwardly from said lateral surface for the distance of said apex from said base;

a plurality of thin, wedged-shaped claws united to said support segments, each of said claws having oppositely disposed edges which meet at a point, and a broad outer face, said claws cojointly defining a conical surface which is concentric to said lateral surface of said body core;

said claws having their broadest end semi-circular in shape and disposed above the plane of the base of said central body core;

the respective claws terminating in a circular array of spaced points lying below said support segments;

said claws being so spaced with respect to each other that their edges define slots along their entire length;

said body core, support segments, and claws defining cylindrical bores parallel to and in communication with, said slots; and

said bores being of greater diameter than the diameter of said circular array upon which said points of said claws terminate.

3. In a positive locking self-centering grapnel utilized in combination with a load having a cylindrical load shaft with a spherical ball attached at the extremity of said shaft the combination comprising;

a cone shaped body core having a base, an apex, and an intervening lateral surface;

a plurality of support segments symmetrically disposed about said body core, integral with said lateral surface, and extending radially and outwardly from said lateral surface for the distance of said apex from said base;

a plurality of thin, wedged-shaped claws united to said support segments, each of said claws having oppositely disposed edges which meet at a point, and a broad face, said claws cojointly defining a conical surface which is concentric to said lateral surface of said body core;

said wedged-shaped claws being so spaced with respect to each other that their edges define slots along their entire length, said slots being greater in width than the diameter of said load shaft and narrower than the diameter of said sphere on said load shaft;

the respective claws terminating in a circular array of spaced points lying below said support segments, said circular array of greater diameter than said load shaft and of smaller diameter than the diameter of said sphere;

said body core, support segments and claws defining cylindrical bores parallel to, and in communication with, said slots, said bores of greater diameter than the diameter of said sphere;

and means for attaching said base of said body to a hoist line.

References Cited in the file of this patent UNITED STATES PATENTS 1,501,138 Rounds July 15, 1924 1,897,920 Wilson et al Feb. 14, 1933 2,510,182 Klingel June 6, 1950 2,828,519 Berg Apr. 1, 1958 FOREIGN PATENTS 785,798 Great Britain Nov. 6, 1957 

